Shingle



Jan. 16, 1951 R, R. MABIE, SR., ETAL 2,538,206

SHINGLE 4 Shee'ts-Sheet 1 Filed June 18, 1948 IN V EN TORS.

N r. R swf m .n w MM 5^.. H WMV. AMB RR Jan. 16, 1951 R, R, MABIE, 5R" ETAL 2,538,206

SHINGLE 4 Sheets-Sheet 2 Filed June 18, 1 948 INVENTORS. RALPH R. MAB/E, 5r: fle/MPH R. MAB/E, Jr. B if f2 ATTQRNEY.

Jan. 16, 1951 R. R. MABIE, sR., ETAL 2,538,205

SHINGLE Filed June 18, 1948 4 sheets-sheet s fZZ f-ZZ i INVENTORS. RALPH R. MAB/E, 5 r. RALF/1' R MAB/E, J' r.

WM/x27@ Jam 16, 1951 R. R. MABIE, sR., ETAL 2,538,206 I SHINGLE Filed June 18, 1948 4 Sheets-Sheet 4 l INVENTORS. RALPH R. MA ,sn RALPH R. MAB Jr.

ATTRNEX Patented Jan. 16, 1951 UNITED STATES PATENT OFFICE SHINGLE Application .lune 18, 1948, Serial No. 33,896

12 Claims.

Our invention relates to shingles, and more particularly to flexible, so-called composition shingles, such as fabric base shingles which are treated with a moisture and weather resistant agent such as a bituminous product.

With shingles of this type, there eXists the desirability of providing butt edges of suicient thickness to simulate the appearance and shadow effect of wood or other rigid shingles when laid on a roof. Also, exible shingles of the type described are apt to curl at the exposed areas unless secured at their butt ends. This tendency is increased by the drying effect caused by exposure to the sun; and frequently the exposed areas are lifted by the wind which causes them to flap back and forth resulting sometimes in breaking of the shingle.

In order to minimize these problems, the courses of the shingles are usually laid close together, and

usually most flexible shingles now in use are so designed that parts of the roof are covered with three thicknesses of material, other parts with two thicknesses, while other parts, particularly the upright joint or slot areas between adjacent shingles have only one thickness. Hence, in order to provide adequate coverage, more material is utilized than would normally be required which results in lack of economy. Some special forms of iiexible shingles are provided with locking means at their butt edges to hold them down,but such arrangement has not been particularly successful` with the ordinary square butt shinglev which `form of shingle is most desirable because of its attractive appearance and conformity in general shape to that long in use in wood shingles.

The patent to Mathews, No. 2,196,420, April 9, 1940, discloses a shingle of the square butt type which is a substantial improvement in solving the problem of prevention of butt end curling or flapping of the shingle, and also of providing sufcient thickness at the butt edge to enhance the appearance of the shingle when laid on a roof. However, in the construction of this shingle, the shingle is folded at the time it is laid. This usually results in cracking of the shingle along the butt edges, which is not only injurious to the shingle but also may result in an unsightly appearance by Virtue of the crack which may form in the decorative mineral coating which covers the shingle, as well as in the base. Furthermore, the folding of the shingle at the time of laying increases the labor time; and considerable nailing is required to hold down the butt ends of the shingle.

Our invention embodies an improvement over the square butt type of shingle disclosed in the aforementioned patent; and it has as its objects, among others, the provision of an improved flexible composition shingle which is secured by means of an underlapping fastening iiap that is preformed so as to obviate cracking along the butt edge, and which at the same time provides a butt edge thicker than the body portion of the shingle, to enhance its appearance; is also so shaped as to provide simple interlocking means adjacent the butt edge to enable the shingle to be securely fastened and at the same time provide a substantially continuous butt line in each course of shingles; which can be rapidly and easily fastened to a substructure by means of a single nail for each shingle, which nail, however, secures more than one shingle; and which shingle is of simple and economical construction and can be economically manufactured by an improved method. Other objects of our invention will become apparent from a perusal of the following description which refers to a preferred embodiment of our invention as illustrative thereof.A

Referring to the drawings:

Fig. 1 is a plan View of the blank for the shingle of our invention before the securing flap portion thereof is underlapped adjacent the underside of the body portion of the shingle;

Fig. 2 is a plan view of the shingle with its preformed underlapped securing flap in position;

Fig. 3 is a vertical section taken in a plane indicated by the line 3--3 of Fig. 2;

Fig. 4 is an enlarged fragmentary plan View of the shingle of Fig. 2 interlocked with an adjacent shingle; portions of the structure being broken away to illustrate more clearly the construction ofthe interlocked joint;

Fig. 5 is a fragmentary section taken in a plane indicated by line 5-5 of Fig. 4.

Fig. 6 is a section similar to Fig. 5 but taken in a diagonal plane through the securing nail; the plane of the section being indicated by line 6 6 in Fig. 7.

Fig. 7 is a fragmentary plan View of overlapping courses of the single of Fig. 2 providing a covering; the upper left hand single portion being shown only partially interlocked, for purposes of illustration, to illu-strate the construction more clearly, and portions of such shingle being broken away for the same purpose.

Fig. 8 is a sectional View taken in a plane indicated byline 8-8 in Fig. 7.

Fig. 9 is an end elevation of the butt line of the lower course of shingles of Fig. 7, looking in the direction of arrow 9 in Fig. '7.

Fig. i is a plan view of a modified form of shingle construction;

Fig. 11 is a section taken in the plane indicated byline II-I I inFig. 10.

Fig. 12 is a plan view of the blank for forming the shingle of Fig. 10.

Fig. 13 illustrates a covering formed by the shingle of Fig. 10.

Fig. 14 is a plan view illustrating the manner in which the single of Fig. 2 may be cut from a parent sheet, and

Fig. 15 is a similar plan view illustrating how the shingle of Fig. 10 can be cut.

Referring to the shingle illustrated in Figs. l through 9, it comprises a blank 2, preferably of any suitable flexible material such as composition roofing material which usually comprises a fabric base, such as felt, impregnated with a water proong composition, such as a bitumen in the form of asphalt. Generally, the base is provided with an asphalt coating of higher melting point than the saturant, as is well known in the art, and the exposed or upper surface of the sheet or base is covered with decorative and also protective coating material 3, usually granular mineral matter such as crushed slate, crushed slag, or the like, which may or may not be colored; the decorative material 3 being indicated by the stippling.

Blank 2 comprises an upper body portion 4 and a lower integral flap portion 6 which is adapted to be underlapped by folding adjacent the underside of body portion 4, as shown by the completed shingle of Fig. 2, along a butt line or edge 1. Thus, flap 6 is hingedly attached to body portion 4. An interlocking, straight slot 8 is formed in the shingle substantially along the line of the butt edge lI, and extends inwardly from one of the side edges 9 of the body portion. The length of the slot ilxes the width of the lateral overlap of a succeeding shingle in the same course. The opposite side edge II` of the body portion is substantially parallel to side edge 9; and the upper and lower edges I2 of the blank are also preferably parallel so that the blank is in the form of a parallelogram. In this connection, butt edge 1. formed by the fold, is parallel to edges I2.

Side edge I3 of flap 6 adjacent slot 8 forms a straight line continuation of side edge 9 of the body portion in the unfolded position of the flap, as can be seen from Fig. 1; while the opposite side edge I4 of flap B also forms a straight line continuation of side edge II in the unfolded position of the ap. Hence, in the form of the blank, side edges 9 and I3 form a continuous edge parallel to the edge formed by side edges II and I4. To enhance the water shedding properties of the shingles when they are laid, the side edges thereof are preferably formed oblique to the vertical, so that the shingle has parallel sloping side edges. As a result, when the flap forming portion 6 is underlapped in the finished shingle of Fig. 2, edge I4 thereof provides a reentrant edge within the confines of the side edges 9 and II of body portion 4, while edge I3 forms the end of a projection I6 adjacent slot 8 which extends beyond the slotted edge 9 of the shingle. In this connection, the direction of the slope of slotted side edge 9, is such that this edge makes an acute angle on body portion 4, with butt edge 'I.

To preclude cracking along butt edge 'I when flap portion 6 is folded adjacent the underside of the shingle, such folding is effected while the asphalt impregnant or coating of the single is still in heated condition and consequently soft. lf

the parent sheet of material from which the shingle is cut does not have the asphalt in a sufciently heated state at the time the shingle is formed, the shingle may be preheated to just below the melting point of the asphalt which will be about 110 to 125 F., depending on the particular grade of asphalt employed, when the fold is made. In this connection, the folding is effected after formation of the slot 8 and on the cut-out blank of the form of Fig. l which has the decorative coating 3 thereon. Since the asphalt is in heated condition when the flap is folded, the mineral granules are only softly imbedded in the asphalt coating, and consequently there will be no cracking that might otherwise occur if the fold is made when the asphalt is thoroughly solidied and consequently set.

A score line may be formed on the undersurface of the shingle to facilitate the folding of the flap, if so desired. To enhance close positioning of flap portion 6 against the underside of body portion 4, gentle pressure may be applied to press the flap against the body portion, or vice versa. When the asphalt has cooled after the folding, flap portion 6 will maintain its preformed position adjacent the underside of the body portion 4 of the shingle by virtue of solidication of the asphalt, but yet will have sufficient flexibility by virtue of its integral hinge connection with the body portion, to enable the shingles to be readily interlocked in a manner to be described.

The shingle may be made of various sizes. In the embodiment illustrated in Figs. 1 through 9, the width thereof (i. e. the distance along edges I2), is preferably about 12 inches, while the height of the shingle (i. e. the vertical distance between edges I2 is also 12 inches). Slot 8 and butt edge line 1 may be any suitable distance from the lower edge I2, but such distance is preferably 11/2 inches in the embodiment illustrated; so that iiap portion 6 is 11/2 inches in height, compared to a 101/2 inch height of the body portion. Slot 8 is preferably 21/2 inches in length, thus providing approximately 21/2 inches lateral overlap of adjacent shingles when they are interlocked; and the angle of the side edges is preferably about 45.

If the slot is of greater length, there may be too much waste of material because we have found 21/2 inches overlap to be satisfactory for most purposes; while if the slot is made much shorter, the lateral overlap may be insufiicient to insure against side leakage. However, it is to be understood that the length of the slot is not particularly critical, and may -vary with the size of the shingle. Neither is the 45 angle particularly critical. We have found this angle to be most desirable for efficient water shedding properties, so as to preclude water from running in between adjacent shingles of a course. However, this angle may be varied within relatively wide limits; and as a matter of fact, no angle is required even if the sides are vertical as the shingle will still interlock lby virtue of the interlocking slots 8, but then too many may be required over a given area to insure against leakage.

The height of flap portion 6 is materially less than the height of Ibody portion 4, being suflicient, depending on the overall height of the shingle body, to provide a ilrm interlock between adjacent shingles. A l to 1% inch underfold is satisfactory for most sizes of the shingles, and compared to the height of the shingle body, the height of the ap is preferably less than 1/3 the height of the shingle body.

76;. Particular reference is made to Fig. 4 which illustrates the manner in which adjacent shingles of a course are fully interlocked, one of which shingles is secured to a roof or any other substructure, such as a side wall, by means of a single nail. For purposes of clarity, the portions of the right hand shingle appearing in Fig. 4 have their reference numerals identified with the letter R while those of the left hand shingle are identified with the letter L When the right hand shingle is laid, a single nail l1 is driven through both the body portion 4R and ap 6R of the right hand shingle at a point adjacent the closed end of slot BR. and a substantial distance above the butt edge 1R.

It is desirable that the nail be driven substantially above the closed end of the slot to locate it as close to the slotted corner as possible for secure fastening of the shingle, but yet avoid the possibility of having the nail driven too far outwardly of the closed end of the slot, as this might interfere with proper overlap of the left hand shingle should reentrant ilap edge |4L engage the nail when the shingles are interlocked. Thus, the closed end of the slot serves as a guide for locating the point at which the nail should be driven. By virtue of the nail penetrating both the body portion and the underlapped ap of the right hand shingle, such shingle is securely fastened at its slotted corner, and the open end of the slot SR is presented to receive the left hand shingle.

In inserting the left hand shingle into the slot, the reentrant side edge portion I4L of flap 6L is inserted between the projecting portion ISR of flap 6R and the underside of body portion 4R as far as the slot permits. As a result, the body portion 4L of the unslotted side of the left hand shingle will overlap the adjacent right hand shingle, and the flap 6L of the left hand shingle Will be held between the right hand ap 6R and the underside of the body portion 4R of the adjacent shingle. Thus each shingle will be positively fastened by a nail at its slotted corner, and interlocked at its opposite corner along the butt edge.

When the adjacent sides of the right and left hand shingles are overlapped, nail Il is fully covered and hence protected. It will be noted that the projecting portion IBR of the right hand flap 6R need not actually project beyond the edge BR, as the interlock will still obtain. However, the projecting portion aids in providing the interlock, and also it is more practical to leave it on than to cut it even with edge SR.

Fig. 7 illustrates a covering formed by the shingle of Fig. 2 in which the shingles are laid in overlapped horizontal courses on a sub-structure 2l which may be a roof, side wall, or any other sub-structure upon which shingles are adapted to be laid. The shingles in each course as shown are laid from right to left, but if de sired, the angle of the side edges may be reversed and the shingles made so that they may be laid from left to right. It will be noted that by virtue of the overlying sloping side edges Il, water is shed properly so that it will not seep through the laterally overlapped adjacent shingles of the respective courses. The position of the upper left hand shingle A appearing in Fig. 7 is shown for purposes of illustration, only partially inserted in the slot 8 formed in the shingle B adjacent thereto.

Nail il penetrates both the body portion 4 and the flap 6 of such adjacent shingle B, and the reentrant edge portion I4 of the shingle A is partially inserted between projection I6 of flap 6 and the body portion 4, of shingle B, with the body portion 4 of shingle A overlying the body portion 4 of shingle B. When shingle A is fully inserted into the slot, nail Il will be fully covered. Although the shingle A of Fig. 7 appears flat in the drawing, inasmuch as the shingle is exible, the interlocking can be readily accomplished by slight bending or ilexing of the shingle if this is necessary.

With respect to the covering illustrated in Fig. 7, the courses of shingles are overlapped a sufcient extent to provide an exposure area in each course of a height of approximately 5 inches. Since the shingle is 101/2 inches in height, as was previously explained, there will be at least a double thickness o-f material over the entire substructure area. Although the double thickness covering may be desirable to insure protection for a roof, it is apparent that the courses may be laid with a greater exposure area; and under such circumstances, certain areas of the covering will only have a single thickness of material while others will have at least a do-uble thickness of material.

In another form of shingle of the same general shape as that of Fig. 2, the shingle blank is 12 inches in width and 9 inches in height with a 1 inch underfold. Thus, the underlapped flap is 1 inch in height, and the preformed shingle is 8 inches in height and l2 inches in Width. The length of the slot is preferably the same as that with respect to the shingle of Fig. 2, in order to provide suillcient lateral overlap for the purposes described. A shingle of these dimensions, can be conveniently laid to provide courses in which the exposure area of each course is 6 inches in height. This results in a single thickness of material over the larger part of the entire covering area, thus effecting economy in material. The question of the thickness of the covering is of course a matter of choice and economy; the main point being that our shingle can be laid to provide at least double thickness of material or substantially a single thickness.

In any event, it will be noted from Fig. 7 that with the courses of the shingles laid as shown, one nail Il driven through the lower left hand slotted corner of each shingle serves to secure positively that shingle and also an underlying shingle in the adjacent lower course of shingles. Since such underlying shingle is also secured at its lower left hand corner by another nail, it will be seen that each shingle is nailed at at least two spaced points, one of which is at its slotted corner and the other in the body portion above the butt edge. Also, each shingle is interlocked with freedom of movement at the butt edge corner opposite to the nailed slotted corner. In case the boards of the sub-structure upon which the shingle is laid should shrink, the interlocked corner serves as an expansion joint, to allow for movement in the supporting sub-structure or in the material itself. This is a very desirable feature in obviating buckling or curling.

Since the shingles are securely fastened at their butt edges, they will be securely fixed against lifting by the wind or otherwise. At the same time, the interlocked butt edges of the shingles of each course will present a substantially con.

tinuous butt line of a thickness much greater than that of the bodies of the shingles, which will produce a marked shadow effect simulating the appearance of wood or similar rigid shingles which have substantial inherent thickness.

Figs.' 10 through 13 illustrate another form of shingle embodying the principle of construction described with respect to the shingle of Figs. 1 and 2, but in which the shingle is provided with slots and is in elongated strip form, to simulate the appearance of individual vertical laid shing.es. As can be noted from the blank of Fig. 12, the slots 22 extend vertically and are equally spaced laterally. Their lower edges extend to the butt line defining butt edge 23 which is formed when flap portion 24 is underfolded in the manner described. Interlocking slot 26 is formed in the same position as in the previously described modication.

However, with this form of shingle, it is desirable to provide a slightly greater lateral overlap than in the previously described modification, and consequently the slot 2li is preferably about 3 inches long. Preferably, the preformed shingle is 101/2 inches in height, with flap 24 of a height of 11/2 inches, and the strip of any desired length. Slots 22 are preferably 1/2 inch wide and 41/4 inches long. These dimensions may be varied, and are given merely for purposes of illustration. 'I'he shingles of Fig. 10 l'are laid and secured in the same manner as that described with respect to Figs. 1 through 9, with the butt edges of shingles in an overlying course adjacent the upper ends of slots 22. When laid, the appearance of the covering will be that as shown in Fig. 13,

wherein the slots 22 produce the effect of individual rectangularly shaped shingles.

As the shingle blanks of our invention are in the form of parallelograms, it is apparent that they may be conveniently cut from a parent sheet of material with substantially no waste. Fig. 14 illustrates a convenient manner in which the shingle blank of Fig. 1 can be cut, by providing spaced diagonal cuts 3l in a continuous strip of the parent sheet to form the side edges of the shingle, and longitudinal cuts 32 to provide the upper and lower edges of the blank. Cuts 33 provide the interlocking slots 8. Theblank of Fig. l2 may be cut in the same way from the continuous strip of the parent sheet, as illustrated in Fig. 15. The slots 22 may be cut out at the same time slots 26 are formed. The cutting pattern of Figs. 14 and 15 is merely illustrative, as there are other apparent ways in which the cutting can be effected, such as the spiral cutting, cross cutting, and staggered cutting well known in the shingle art.

We claim:

1. A shingle comprising a body portion having side edges and a flap underlapping the underside of the body portion providing a butt edge thicker' than said body portion, a slot being formed in said shingle substantially on the line of said butt edge and extending from one of said side edges to provide for interlocking of said shingle with an adjacent similar shingle.

2. A shingle comprising a body portion having side edges and a ap underlapping the underside of the body portion providing a butt edge thicker than said body portion, the height of said flap being materially less than that of the body portion, and a slot being formed in said shingle substan tially on the line of said butt edge and extending from one of said side edges to provide for interlocking of said shingle with an adjacent similar shingle.

3. A flexible shingle comprising a, body portion having substantially parallel sloping side edges and a preformed flap underlapping the underside of the body portion providing a butt edge thicker than said body portion, the slope of one of said side edges forming an acute angle on said body portion between said butt edge and said one side edge, and .a slot being formed in said shingle substantially on the line of said butt edge and extending from said acute angle forming side edge to provide for interlocking of said shingle with an adjacent similar shingle.

4. A flexible shingle comprising a body portion having substantially parallel sloping side edges and a preformed flap underlapping the underside of the body portion providing a butt edge thicker than said body portion, the side edges of the flap when unfolded forming straight line continuations of the side edges of the body portion whereby the underlapped flap has a, projection beyond one of said side edges of the body portion, and a slot being formed in said shingle substantially on the line of said butt edge and extending from the last mentioned side edge of the body portion to provide for interlocking of said shingle with an adjacent similar shingle.

5. A flexible shingle comprising a body portion having substantially parallel sloping side edges and a preformed flap underlapping the underside of the bodyportion providing a butt edge thicker than said body portion, the side edges of the flap when unfolded forming straight line continuations of the side edges of the body portion whereby the underlapped flap has a projection beyond one of said side edges of the body portion, the height of said ap being less than one-third that of the body portion, and a slot being formed in said shingle substantially on the line of said butt edge and extending from the last mentioned side edge of the body portion to provide for interlocking of said shingle with an adjacent similar shingle.

6. A covering comprising overlapping courses of shingles; each of said shingles comprising a body portion and a flap underlapping the underside of the body portion providing a butt edge thicker than said body portion, a slot being formed in said shingle substantially on the line of said butt edge and extending from one of said side edges; the adjacent shingles in each course overlapping laterally and being interlocked at such slots whereby each course is provided with a substantially continuous butt line of said butt edges.

'7. A covering comprising overlapping courses of shingles; each of said shingles comprising a body portion and a preformed flap underlapping the underside of the body portion providing a butt edge thicker than said .body portion, a slot being formed in said shingle substantially on the line of said butt edge and extending from one of said side edges; the adjacent shingles in each course overlapping laterally and being interlocked at such slots whereby each course is provided with a substantially continuous butt line of said butt edges, each shingle of a course being secured at one corner by a nail penetrating both the body portion and the flap of such shingle adjacent said slot, and each nail being covered by an adjacent shingle.

8. A covering comprising overlapping courses of shingles; each of said shingles comprising a body portion and a ap underlapping the underside ofthe body portion providing a butt edge thicker than said body portion, a slot being formed in said shingle substantially on the line of said butt edge and extending from one of said side edges; the adjacent shingles in each course overlapping laterally and being interlocked at such slots whereby each course is provided with a substantially continuous butt line of said butt edges, each shingle of a course being secured at one corner by a nail penetrating both the body portion and the flap of such shingle adjacent said slot, each nail being covered by an adjacent shingle, and each of said nails in shingles of an overlying course also penetrating the body p01'- tion of a shingle in an underlying course whereby each shingle is nailed at at least two spaced points and the interlocked butts provide expansion joints.

9. A covering comprising overlapping courses of shingles; each of said shingles comprising a body portion having substantially parallel sloping side edges and a flap underlapping the underside of the .body portion providing a butt edge thicker than said body portion, the slope of one of said side edges forming an acute angle on said body portion between said butt edge and said one side edge, and a slot being formed in said shingle substantially on the line of said butt edge and extending from said acute angle forming side edge; the shingles in each course being interlocked at such slots with the body portion of the unslotted side of each shingle overlapping the body portion of an adjacent shingle and with the ap at said unslotted side between the flap and the body portion of such adjacent shingle.

10. A covering comprising overlapping courses of flexible shingles; each of said shingles comprising a body portion having substantially parallel sloping side edges and a ilap underlapping the underside of the body portion providing a butt edge thicker than said body portion, the slope of one of said side edges forming an acute angle on said body portion between said butt edge and said one side edge, a slot being formed in said shingle substantially on the line of said butt edge and extending from said acute angle forming side edge, and the side edges of the flap when unfolded forming straight line continuations of the side edges of the body portion whereby the underlapped flap has a projection beyond one of said side edges of the body portion; the shingles in each course being interlocked at such slots with the body portion of the unslotted side of each shingle overlapping the body portion of an adjacent shingle and with the flap at said unslotted side between the projecting portion of the flap and the body portion of such adjacent shingle, each shingle of a course being secured at one corner by a nail penetrating both the body portion and the flap of such shingle adjacent said slot, and each nail being covered by an adjacent shingle.

11. A exible shingle comprising a body portion having substantially parallel sloping side edges and a preformed integral ap of the same material as said body portion underlapping the` underside of the body portion and providing a butt edge thicker than said body portion, said butt edge being substantially parallel to the upper edge of said body portion, the side edges of the flap when unfolded forming straight line continuations of the side edges of the lbody portion whereby the underlapped flap has a projection at one end thereof extending beyond one of said side edges of the body portion and a reentrant edge at the opposite end of said flap, the height of said flap being less than one-third that of the body portion, and a slot being formed in said shingle substantially on the line of said butt edge and substantially parallel to said upper edge of said body portion, said slot extending from the sloping side edge of the shingle beyond which said ilap projects to provide for interlocking of said shingle with an adjacent similar shingle with the reentrant edge portion of said nap adapted to lie between the projecting flap portion and the body of such adjacent shingle.

12. A covering comprising overlapping courses of shingles each having the construction of claim 11, in which each shingle of a course is secured at one butt edge corner by a single nail penetrating both the body portion and the ap of such shingle at a point adjacent the closed end of the slot in such shingle, said shingle nail also penetrating the body portion of an underlying shingle in an adjacent lower course of such shingles whereby each shingle is nailed at two spaced points, the opposite butt edge corner of each shingle being merely interlocked in the slot of an adjacent shingle whereby such opposite butt edge corner serves as an expansion joint, and each nail being covered .by the body portion of an adjacent shingle.

RALPH R. MABIE, Sx. RALPH R. MABIE, JR.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,531,151 Steele Mar. 24, 1925 1,658,806 Kaufer Feb. 14, 1928 2,196,420 Matthews Apr. 9, 1940 

